001////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code for adherence to a set of rules.
003// Copyright (C) 2001-2020 the original author or authors.
004//
005// This library is free software; you can redistribute it and/or
006// modify it under the terms of the GNU Lesser General Public
007// License as published by the Free Software Foundation; either
008// version 2.1 of the License, or (at your option) any later version.
009//
010// This library is distributed in the hope that it will be useful,
011// but WITHOUT ANY WARRANTY; without even the implied warranty of
012// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
013// Lesser General Public License for more details.
014//
015// You should have received a copy of the GNU Lesser General Public
016// License along with this library; if not, write to the Free Software
017// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
018////////////////////////////////////////////////////////////////////////////////
019
020package com.puppycrawl.tools.checkstyle;
021
022import java.io.File;
023import java.io.IOException;
024import java.util.regex.Pattern;
025
026import com.puppycrawl.tools.checkstyle.api.CheckstyleException;
027import com.puppycrawl.tools.checkstyle.api.DetailAST;
028import com.puppycrawl.tools.checkstyle.api.DetailNode;
029import com.puppycrawl.tools.checkstyle.api.FileText;
030import com.puppycrawl.tools.checkstyle.api.TokenTypes;
031import com.puppycrawl.tools.checkstyle.utils.JavadocUtil;
032import com.puppycrawl.tools.checkstyle.utils.TokenUtil;
033
034/**
035 * Class for printing AST to String.
036 */
037public final class AstTreeStringPrinter {
038
039    /** Newline pattern. */
040    private static final Pattern NEWLINE = Pattern.compile("\n");
041    /** Return pattern. */
042    private static final Pattern RETURN = Pattern.compile("\r");
043    /** Tab pattern. */
044    private static final Pattern TAB = Pattern.compile("\t");
045
046    /** OS specific line separator. */
047    private static final String LINE_SEPARATOR = System.lineSeparator();
048
049    /** Prevent instances. */
050    private AstTreeStringPrinter() {
051        // no code
052    }
053
054    /**
055     * Parse a file and print the parse tree.
056     * @param file the file to print.
057     * @param options {@link JavaParser.Options} to control the inclusion of comment nodes.
058     * @return the AST of the file in String form.
059     * @throws IOException if the file could not be read.
060     * @throws CheckstyleException if the file is not a Java source.
061     */
062    public static String printFileAst(File file, JavaParser.Options options)
063            throws IOException, CheckstyleException {
064        return printTree(JavaParser.parseFile(file, options));
065    }
066
067    /**
068     * Prints full AST (java + comments + javadoc) of the java file.
069     * @param file java file
070     * @return Full tree
071     * @throws IOException Failed to open a file
072     * @throws CheckstyleException error while parsing the file
073     */
074    public static String printJavaAndJavadocTree(File file)
075            throws IOException, CheckstyleException {
076        final DetailAST tree = JavaParser.parseFile(file, JavaParser.Options.WITH_COMMENTS);
077        return printJavaAndJavadocTree(tree);
078    }
079
080    /**
081     * Prints full tree (java + comments + javadoc) of the DetailAST.
082     * @param ast root DetailAST
083     * @return Full tree
084     */
085    private static String printJavaAndJavadocTree(DetailAST ast) {
086        final StringBuilder messageBuilder = new StringBuilder(1024);
087        DetailAST node = ast;
088        while (node != null) {
089            messageBuilder.append(getIndentation(node))
090                .append(getNodeInfo(node))
091                .append(LINE_SEPARATOR);
092            if (node.getType() == TokenTypes.COMMENT_CONTENT
093                    && JavadocUtil.isJavadocComment(node.getParent())) {
094                final String javadocTree = parseAndPrintJavadocTree(node);
095                messageBuilder.append(javadocTree);
096            }
097            else {
098                messageBuilder.append(printJavaAndJavadocTree(node.getFirstChild()));
099            }
100            node = node.getNextSibling();
101        }
102        return messageBuilder.toString();
103    }
104
105    /**
106     * Parses block comment as javadoc and prints its tree.
107     * @param node block comment begin
108     * @return string javadoc tree
109     */
110    private static String parseAndPrintJavadocTree(DetailAST node) {
111        final DetailAST javadocBlock = node.getParent();
112        final DetailNode tree = DetailNodeTreeStringPrinter.parseJavadocAsDetailNode(javadocBlock);
113
114        String baseIndentation = getIndentation(node);
115        baseIndentation = baseIndentation.substring(0, baseIndentation.length() - 2);
116        final String rootPrefix = baseIndentation + "   `--";
117        final String prefix = baseIndentation + "       ";
118        return DetailNodeTreeStringPrinter.printTree(tree, rootPrefix, prefix);
119    }
120
121    /**
122     * Parse a file and print the parse tree.
123     * @param text the text to parse.
124     * @param options {@link JavaParser.Options} to control the inclusion of comment nodes.
125     * @return the AST of the file in String form.
126     * @throws CheckstyleException if the file is not a Java source.
127     */
128    public static String printAst(FileText text, JavaParser.Options options)
129            throws CheckstyleException {
130        final DetailAST ast = JavaParser.parseFileText(text, options);
131        return printTree(ast);
132    }
133
134    /**
135     * Print branch info from root down to given {@code node}.
136     * @param node last item of the branch
137     * @return branch as string
138     */
139    public static String printBranch(DetailAST node) {
140        final String result;
141        if (node == null) {
142            result = "";
143        }
144        else {
145            result = printBranch(node.getParent())
146                + getIndentation(node)
147                + getNodeInfo(node)
148                + LINE_SEPARATOR;
149        }
150        return result;
151    }
152
153    /**
154     * Print AST.
155     * @param ast the root AST node.
156     * @return string AST.
157     */
158    private static String printTree(DetailAST ast) {
159        final StringBuilder messageBuilder = new StringBuilder(1024);
160        DetailAST node = ast;
161        while (node != null) {
162            messageBuilder.append(getIndentation(node))
163                    .append(getNodeInfo(node))
164                    .append(LINE_SEPARATOR)
165                    .append(printTree(node.getFirstChild()));
166            node = node.getNextSibling();
167        }
168        return messageBuilder.toString();
169    }
170
171    /**
172     * Get string representation of the node as token name,
173     * node text, line number and column number.
174     * @param node DetailAST
175     * @return node info
176     */
177    private static String getNodeInfo(DetailAST node) {
178        return TokenUtil.getTokenName(node.getType())
179                + " -> " + escapeAllControlChars(node.getText())
180                + " [" + node.getLineNo() + ':' + node.getColumnNo() + ']';
181    }
182
183    /**
184     * Get indentation for an AST node.
185     * @param ast the AST to get the indentation for.
186     * @return the indentation in String format.
187     */
188    private static String getIndentation(DetailAST ast) {
189        final boolean isLastChild = ast.getNextSibling() == null;
190        DetailAST node = ast;
191        final StringBuilder indentation = new StringBuilder(1024);
192        while (node.getParent() != null) {
193            node = node.getParent();
194            if (node.getParent() == null) {
195                if (isLastChild) {
196                    // only ASCII symbols must be used due to
197                    // problems with running tests on Windows
198                    indentation.append("`--");
199                }
200                else {
201                    indentation.append("|--");
202                }
203            }
204            else {
205                if (node.getNextSibling() == null) {
206                    indentation.insert(0, "    ");
207                }
208                else {
209                    indentation.insert(0, "|   ");
210                }
211            }
212        }
213        return indentation.toString();
214    }
215
216    /**
217     * Replace all control chars with escaped symbols.
218     * @param text the String to process.
219     * @return the processed String with all control chars escaped.
220     */
221    private static String escapeAllControlChars(String text) {
222        final String textWithoutNewlines = NEWLINE.matcher(text).replaceAll("\\\\n");
223        final String textWithoutReturns = RETURN.matcher(textWithoutNewlines).replaceAll("\\\\r");
224        return TAB.matcher(textWithoutReturns).replaceAll("\\\\t");
225    }
226
227}